function probe = getAppearProbes( config , method )

    dataset_n  = length( config.datasets );

    if nargin < 2
        method = config.appear_probe_method;
    end

    probe = cell( 1, dataset_n );

    for dataset_i = 1: dataset_n

        probe{ dataset_i }  = ...
            getAppearProbe( config.datasets{ dataset_i } , method );

    end

end

function probe = getAppearProbe( config, method)            
    
    n = length( config.src_list );        
    
    try
        toc;
    catch
        tic;
    end
    
    timer = toc;
    
    for j = 1:n
        src_name = [config.src_root config.src_list{j}];
        
        img = imread( src_name );
        
        if j ==1
            temp = method( img );
            dim = size( temp, 2);
            probe = zeros( n , dim );
            probe(j,:) = temp;
        else
            probe(j,:) = method( img );
        end
        
        if( mod(j,20) == 0)
            if( toc - timer > 10)
                imagesc( probe );
                drawnow;
                timer = toc;
            end
        end
    end    
end